Various types of cutting instruments and machines have found use in shaping different kinds of flat materials. Leather-, paper-, and metal-cutting tools represent popular examples of these.
Mats used in framing photographs and other pictures must also undergo shaping prior to their use. In particular, they must have an appropriately shaped hole cut into them to provide the esthetically pleasing framing for the drawing or other objects with which it finds use. Cutting this inside opening presents particular problems not encountered when cutting the outer edges of the mat or with the other types of materials mentioned above. To provide a pleasing frame for its picture, the inner opening of the mat must have a bevelled edge directed in towards the picture. Even though the mat only has a composition of cardboard, cutting this bevelled edge accurately and precisely represents a most difficult problem.
To provide a thin slit in the mat when cutting this opeing, most cutters employ a blade held in some form of a clamp. The cutter tilts the clamp and thus the blade at an angle relative to its base to provide the bevelled edge. The thin blade allows, of course, for the production of a sharp precise slit into the matting material. Examples of this type of mat cutter appear in, inter alia, U.S. Pat. Nos. 611,238 to P. Drinkaus, 3,130,622 to W. F. Eno, 3,213,736 to W. B. Keeton, 3,463,041 to M. Shapiro et al., and 3,527,131 to C. Elberin et al.
A thin blade, such as a razor blade, should encounter minimal reisitance and friction as it enters into and cuts through the matting material. Nonetheless, it still does not provide for a perfectly precise bevelled edge on the inside of the matting frame. The blade demonstrates a tendency to flex or "walk", which results in deviations from perfection. This fault almost always appears in the inner corners of mats having bevelled edges. To minimize these deviations, most mat cutters place their blade at an angle no greater than 30.degree. relative to the normal of the surfaces of the matting material. This unfortunately represents a severe limitation since a 45.degree. angle would provide a larger bevelling effect, a more pleasing appearance, and allow the use of thinner mats. The presently used mat cutters, consequently, do not produce the desired 45.degree. bevel and have serious imperfections in the mats they do produce.